Based on satellite imagery and direct observations by CVGHM, the Darwin VAAC reported that on 11 April a diffuse plume from Batu Tara rose to an altitude of 1.5 km (5,000 ft) a.s.l. and drifted W. On 17 April, CVGHM lowered the Alert Level from 3 to 2 (on a scale of 1-4).

Geological Summary. The small isolated island of Batu Tara in the Flores Sea about 50 km N of Lembata (fomerly Lomblen) Island contains a scarp on the eastern side similar to the Sciara del Fuoco of Italy's Stromboli volcano. Vegetation covers the flanks to within 50 m of the summit. Batu Tara lies north of the main volcanic arc and is noted for its potassic leucite-bearing basanitic and tephritic rocks. The first historical eruption, during 1847-52, produced explosions and a lava flow.

Sources: Pusat Vulkanologi dan Mitigasi Bencana Geologi (PVMBG, also known as CVGHM), Darwin Volcanic Ash Advisory Centre (VAAC)